I would say go used - but get at least 105 level componetry if you're planning on doing centuries and such.

I'd also say test ride a bunch of aluminum bikes with carbon fiber forks - especially on chipseal if that's common where you ride - because I found aluminum even with carbon fork very harsh, especially on long rides. your townie is probably fairly cush with big tires that are cushioning your ride. So you might want to explore steel, carbon or titanium frames - or at least carbon fiber seat stays on an aluminum frame (that made a huge difference to me)